sunglasses to see invisible luminous ink
Maybe it's me, but I don't recall seeing too many spy movies where the spy actually carried an infrared light around in his/her pocket. I'm sure it's happened. They do it on CSI.
But I would think that the intrinsic problem with carrying a thin rod of glass filled with gases around in your pocket would be... well, dangerous unless you had some sort of cover over it. And, if the movies are to be believed (they're not, but just go with me here) the inevitable gunfight would put that rod of glass in peril-along with your leg, as it would cut right into you.
This would definitely be the case if you were in a John Woo film. Lots of diving around with two guns and doves flying all over the place. All in slow motion. So the camera could catch the agony in your face as the glass shatters into your leg.
So, how would you be able to read a message written in invisible ink without your IR light?
These are the VID8000 Glasses. They allow you to see in the same spectrum as the ink written by this pen:
We all understand the idea of invisible ink. It was around when I was a kid, and continues to be of fascination to kids and adults alike just because the idea of secret messages is just... well... cool. However, back in those days the pens didn't look very nifty. The looked sort'a like Sharpies and came with a book of crosswords and word searches. For the life of me, I can't remember how invisible ink and a word search integrated into something fun...
But invisible ink is still alive and well. Here's how your written message looks without the glasses: